Abstract

Biodegradation of organic flotation collectors, namely sodium isopropylxanthate, dodecylammonium acetate and sodium oleate in solution, was studied using Bacillus polymyxa. The biodegradation has been assessed under different conditions, namely during growth, in the presence of the cells, metabolite or an active culture. Xanthate biodegradation was found to be better in the presence of an active culture or metabolite, while the biodegradation of dodecylammonium acetate was more efficient during bacterial growth. The efficacy of biodegradation of sodium oleate was the highest using an active culture. The growth of the organism could be successfully achieved in the presence of the organic collectors. The surface chemical changes brought about by the interaction between the minerals, namely galena, quartz or calcite and collector, metabolite or cells served as indicators of the biodegradation process. The biological stripping of the adsorbed collector reagents from mineral surfaces was also confirmed by FTIR spectroscopy.